If the Front standard is not square to the bed and body then moving the bed out of square will not fix the problem. Moving the bed out of square will induce rise or fall and the front standard error angle may come back into play as the lens focus is changed from the point it was when the bed was repositioned.

Bed Check
_________________The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU.

I focussed the lens at infinity using the ground glass, then removed the top RF housing, loosened the grub screw on the armature connecting to the rangefinder moving mirror, rotated the mirror until the images aligned, then tightened the grub screw.

All appears to be well, probably not the ideal method but better than trying to cut a master cam.